I've been layering azola from the pond, kitchen garbage, and old
compost to a pile that suddenly is riddled with nightcrawlers. The
worms are consuming the kitchen scraps in a day or two and the pile is
warm. Is this typical for a compost pile to turn into a worm farm? I
guess it's time to go fishin'

HA! Not on your life -- you're a lucky man (or woman, whichever the case
may be)!

The worms will help break down the organic materials and turn them into
good, healthy food for your plants. It is my understanding that they
will work their way up from the bottom as they eat -- when they get to the
top you can move 'em to another pile to get started munching that one down
as well.

Folks pay good money for worm droppings -- there are whole businesses that
do nothing but put worms to work making good gardening stuff.

James